Failed marriage, now what?

My husband ended up saying he wanted a break one day. Then he slept with some other mother with kids after I had just had our newborn two months prior. We wanted to get married and stay together and have a baby. We tried so hard and got our baby girl. But for what? He ended up hating his life and blamed everything on me even though it was his fault he didn’t finish school, like his job, like his weight. I’m living with him until our lease is up in November of this year and also because he doesn’t want to be excluded from our baby’s life. He claims he is going through a phase where he knows he’s hurt me because he misses being free I suppose, you know, new relationship cause it’s fun and no expectations need to be met. And now he’s saying maybe we could end up together again in the future. How am I supposed to feel after her slept with someone on the break, talks to her like she’s his now, and sees her at work all the time? Like seriously? After all the sacrifices I made as a wife and friend, now he wants to have a mid life crisis at 25 yrs old while I’m stuck unhappy and miserable? I’m basically a single mom at this point with no job, no friends, and no life, while he’s happy living whatever life he wanted. I guess I need some encouragement. Some words to help me feel better about me, weight loss tips for my postpartum belly, how to get a new job and where fast, how to start talking to guys because I know a lot of men don’t like moms with kids. This is all so hard. Has anyone else gone through this or is?